The present invention relates to a spinneret holder assembly for producing a continuous plastic multiple-component yarn with a preset component ratio.
It is known that conventional spinneret holder assemblies for single-component products, used in continuous-type extrusion heads, are substantially constituted by three superimposed plates joined by bolts which can be assembled in a suitable seat formed in the extrusion head.
The three plates that are used are constituted by a first plate, which conveys the melted plastic material from the head into the extrusion pack through a hole which is generally located at the center of the plate; a second plate, which is constituted by a border which adheres to the upper plate, preventing the escape of the polymer that flows between the two plates; and a perforated region inside the border which distributes the material over the underlying plate; there is also provided a third plate, known as spinneret, which is designed to convey the polymer through a very specific number of holes in order to obtain a corresponding number of filaments which constitute the continuous yarn after cooling.
Moreover, meshes are generally provided above the second plate and are designed to filter the polymer.
When it is necessary to produce a two-component continuous yarn, a relatively large number of plates is interposed between the first plate, which generally has two inlets, and the spinneret, in order to appropriately guide the two components so that the two components reach each hole of the spinneret in the same quantitative ratio.
In order to achieve this result and ensure that the same amount of each component reaches each hole, current solutions use paths, for both components, which always have the same length and cross-section, so that the quantitative ratios assuredly remain unchanged.
This kind of solution entails an extremely complicated mechanical structure which arises from a large number of mutually superimposed and assembled plates and in which it is necessary to form a plurality of channels, so as to achieve the intended conveyance of the components.
The aim of the present invention is to solve the above-cited problem, providing a spinneret holder assembly which allows to produce a continuous multiple-component yarn without thereby requiring a large number of plates.
Within the scope of this aim, an object of the present invention is to provide a spinneret holder assembly in which it is possible to preset the quantitative ratios between the two components, with the assurance that each component is present in the final yarn always in the same quantitative ratio.
Another object of the present invention is to provide a spinneret holder assembly which, thanks to its particular constructive characteristics, is capable of giving the greatest assurances of reliability and safety in use.
Another object of the present invention is to provide a spinneret holder assembly which can be easily obtained starting from commonly commercially available elements and materials and is also competitive from a merely economical point of view.
This aim, these and other objects which will become better apparent hereinafter are achieved by a spinneret holder assembly for producing a continuous plastic multiple-component yarn with a preset component ratio, according to the present invention, characterized in that it comprises, in a mutually superimposed arrangement: a plate for conveying a first component and at least one second component; a distribution plate with first channels for the passage of said first component and a first compensation element for said second component; a pre-spinneret with second channels for the passage of said first component which are aligned with said first channels and a second compensation element for said second component; and a spinneret with extrusion holes which are connected to said channels for the passage of said first component and extend from a region for the distribution of said second component; the paths followed by said first component and said at least one second component being different one another and the load loss of the various paths that are covered being identical for each component, for a constant ratio between the components of each filament that leaves said spinneret.